Digital cameras are typically configured to capture a digital image or digital video of a photographic scene. An optical lens assembly focuses an incoming light field from the photographic scene onto an electronic image sensor, configured to generate an electronic representation of the photographic scene. The electronic representation may be converted to a digital image, or sequence of digital images comprising a digital video.
The optical lens assembly typically focuses items within a field of view of the photographic scene, according to a focal length of the optical lens assembly. Photographers conventionally employ lens focal length (zoom), and the physical position of a digital camera to provide appropriate perspective to capture a desired image. However, positioning the digital camera in the appropriate perspective is not always practical. Furthermore a different perspective may be needed after an image is captured and the photographic scene has changed.
Videographers sometimes employ a dolly rail apparatus to control camera position, along with a predetermined lens profile for zoom and focus to maintain the appearance of a foreground subject's size in the video sequence while changing the perspective relative to a scene background. This technique is referred to in the art as the dolly zoom. However, a dolly apparatus and/or a camera lens with a precisely controllable variable focal length are not always available or practical in common video capture settings, such as video capture with a mobile device or smart phone. Thus, there is a need for addressing these issues and/or other issues associated with the prior art.